Option to key amount/comments for approve

Eg, I want the customer to add the transaction code they made using offline payment.

Some of my customers would like to sign up for long term but they faced some issue and prefer to pay in small amount for a 1 year membership.

Eg my 1 year membership fee cost SGD 288, but they want to pay in small sum of $50 whenever they can pay but they want to enjoy the 1 year membership fee amt instead of pay $88 per month which is much more expensive.

In other words, they want to pay $50 for 1st mth, another $100 on the second month and 3rd month the remaining, can they update the system to reflect the balance.

Is there any option for them to fill in the amount they want to pay as currently I am tracking manually on excel and had to contact them to top the next amount?

I cannot use Paypal/Skrill due to paypal/skrill does not allow skill of game of chance to be included their payment scheme and I had to opt for offline payment.


2.For the fields to add so that once they made the offline payment, they can update the transaction mode in their membership profile so that I receive the payment as currently this method is done through by the customers after sending me a facebook message that they had made offline payment from bank to bank.